The Edwards Aquifer is the lifeblood of for dozens of communities – and millions of people – in Central and SouthCentral Texas. So too for over 60 species of plants and animals that live in the Edwards Aquifer Ecosystem and nowhere else on the planet.

Despite the immeasureable value of this natural resource, human activity – urbanization – now threatens to taint the water of the Edwards Aquifer with a slew of pollutants – from fertilizers and pesticides to toxic metals and sewage spills.

The Edwards Aquifer and its Great Springs are highly vulnerable because of their unique geology and hydrology. Caves, sinkholes, faults, and fractures dot the landscape of the Recharge Zone, where water plunges underground, where it encounters limestone rock that as been eroded over time to create large underground channels for the water to flow.

Water in the Edwards Aquifer moves at a rate of thousands of feet per day; compared to velocities of a few feet per year in other aquifers. This rapid movement and the relatively large size of the spring outlets provide none of the filtration, absorption, and slow water flow that protect many aquifers from contamination.

Development in the Recharge Zone and upstream of the Recharge Zone in the Contributing Zone of new subdivisions, shopping centers, office buildings, highways, golf courses, sewer lines, wastewater treatment plants, and rock quarries all create increased risk of contamination of the aquifer.

We are literally poisoning our drinking water when we allow development to take place that will undeniably increase loads of pollutants over the sensitive karst limestone aquifer.

Urban development creates numerous sources of water pollution. First, the construction phase transforms farm, ranch, forest, and pasture land into large areas of disturbed soil. Central Texas’ erratic weather patterns can dump 6-10 inches of rainfall in a short time span. Erosion and sedimentation controls at construction sites are often overwhelmed by heavy rains and the result is muddy run-off leaving the site and entering a creek and eventually the aquifer and springs.

Large scale construction activity leads to increased sediment loads that wash off of construction sites.
At right, silt fences are not capturing sediment-laden runoff at a highway construction site.

When construction is completed, the development transforms pervious land into impervious cover, which means any surface that water cannot pass through, such as roofs, parking lots, and roads. These surfaces prevent rainfall from being filtered through vegetation and absorbed by soil, thereby increasing the percentage of rainfall that becomes storm water. Rainfall that hits pavement washes oil, grease, and other urban contaminants off their surfaces and into creeks, streams and recharge features. Increased impervious cover also leads to increased flooding and erosion of stream banks, which results in higher levels of sediments entering the aquifer and emerging at the Springs.

New developments typically are required to install “water quality controls” or “best management practices,” engineered structures designed to capture the “first flush” of stormwater runoff, which has a higher percentage of pollutants. The “first flush” is routed into a pond or filter that removes some pollutants. However, no structured control achieves 100% removal of pollutants. Click here to read a U.S. Geological Survey report on performance of structured controls. In some instances, the structured controls accumulate pollutants that are then washed out of the control by a very heavy rain event. The bottom line is that history has proven engineered controls cannot and do not prevent pollution of water in the Edwards Aquifer watershed.

Increased urbanization of the Edwards Aquifer has led to increased numbers of vehicles traveling over the aquifer. In turn, this has led to increased contaminants from automobiles, such as polycyclic aromatic hydrocarbons (or PAHs), entering the aquifer. Most roadways over the aquifer do not have “water quality controls” to capture these contaminants that are continually emitted by vehicles.

Increased numbers of residential subdivisions over the aquifer has led to increases in fertilizers, pesticides, fungicides, and other house hold chemicals that wash off of lawns and end up in the aquifer and springs. Golf courses are also a leading source of these contaminants, as Hill Country soils are not capable of supporting golf turf without massive chemical applications to provide nutrients and fend off insects and fungi.

Increased and concentrated residential development also creates miles of sewer pipes, which can crack and leak without being detected, sometimes dumping raw sewage into fractures and fissures. Sewage lift stations can fail, and sewer manholes can overflow.

We advocate for prevention of pollution of the Edwards Aquifer by preventing the type of developments that threaten our water and endangered species. In fact, it would be cheaper to protect the Edwards Aquifer through conservation easements and parklands purchases than it would cost taxpayers to build the roads, schools, water and wastewater systems for development that threatens our water.

In sum, the Edwards Aquifer watershed is too vulnerable to accommodate the influx of new residents that business boosters and developers would like to see.

Overpumping and Rule of Capture
The Edwards Aquifer provides drinking water for over 1.7 million people. The Austin/San Antonio corridor is expected to grow continually, requiring more water if new growth is wasteful and not sustainable. Current pumping form the aquifer has resulted in diminished pring flows in San Antonio.

Water hustlers are trying to secure rights to pump tremendous amounts of water out of the western reaches of the Edwards Aquifer to pipe and sell to other parts of the state. Texas’ antiquated “Rule of Capture” allows people to pump as much water from underneath their property as they please, even if in doing so they cause their neighbors’ wells to go dry.

Groundwater districts have been established in most parts of Texas to regulate groundwater pumping from different aquifers. The Edwards Aquifer Authority regulates most of the Southern Segment of the Edwards Aquifer, including San Marcos, New Braunfels, San Antonio, and Uvalde. The Barton Springs Edwards Aquifer Conservation District regulates pumping in the Barton Springs segment.

Development interests regularly try to weaken pumping restrictions to protect spring flows for endangered species, as well as for the health of downstream rivers and coastal ecosystems – and economies.

How can this region continue to grow without pumping aquifers dry? Reducing consumption of water reduces perceived need to build new reservoirs or drill deeper wells. Rainwater harvesting can provide residential development with adequate – and tasty – water without surface or ground water. Improving efficiency of transmission lines and appliances can save millions of gallons of water each day.

Infrastructure and Development
The Texas Hill Country and Edwards Aquifer region is under assault from urban sprawl. Farms and ranches are being turned into subdivisions, shopping centers, and highways. This pattern of unsustainable growth is threatening to pollute and over-pump the watersheds that replenish the Edwards Aquifer and the Great Springs of Texas, including drinking water for over 1.7 million Texans.

For decades, the rugged terrain and scarcity of water in the Hill Country kept urban and suburban development at bay, while the flatter, more fertile eastern edge of the Balcones Escarpment supplied resources for growth and development. But modern construction equipment, speculative real investment, and government subsidies are transforming the Hill Country into Everywhere U.S.A. All of these ingredients in urbanization come together in providing infrastructure for development: roads, sewer lines, and water lines. This infrastructure is often subsidized by us, the taxpayers.

New roadways built by TxDOT and water pipelines built by the Lower Colorado River Authority and Guadalupe Blanco River Authority into the Hill Country enable the development of large residential subdivisions, creating thousands of new commuters living on the Edward Aquifer. The residential growth brings increased traffic, sewage, and higher taxes to pay for schools and services.

We, the people, are literally paying for the pollution of our fragile aquifer when our tax dollars are spent paving the Hill Country and piping in water from elsewhere, and piping out sewage over the sensitive Edwards Aquifer ecosystem. Rapid urbanization also draws more water from our aquifers, threatening spring flows, agricultural users, and downstream needs, like coastal bays and estuaries.

What can we do to protect the Hill Country and Edwards Aquifer?

First, let’s stop making matters worse and not build new highways and other infrastructure into the Hill Country and Edwards Aquifer. To use the motto from San Antonio: “Not on our aquifer; not with our money.” Rainwater harvesting and aggressive conservation can provide adequate supplies for a growing population.

Second, let’s preserve Hill Country ranches, farms, and open space. Farming and ranching families are under pressure to sell to developers. It would be far less expensive for tax-payers to invest in conservation easements, parks, and preserves over the Edwards Aquifer than it would be to pay for all of the roads and pipelines planned to serve new development. A bold effort across the Edwards Aquifer region is needed to preserve our Hill Country heritage and protect water quality and quantity in our Great Springs and beautiful Texas rivers.

What can you do to get involved? Join the Greater Edwards Aquifer Alliance today. Sign our petition to elected officials demanding clean water for Texas.

Texas Quarries
The Edwards Aquifer, and other aquifer in Texas, are being blasted, chopped, and dug up. Often the limestone rock is crushed at the site of the quarry before being hauled off in large trucks, frequently to road construction sites.
  • Currently there are no adequate state regulations to protect groundwater, surface water, or adjacent communities from the impacts of the rock crushers and quarries.
  • Where these facilities are located in Edwards Limestone, the underlying aquifer is particularly vulnerable to contamination, whether or not the quarry actually excavates to below the aquifer water level.
  • Local communities experience air quality degradation, dangerous roadways with higher traffic volume, and water quality degradation. They have no voice, however, in quarry or crusher siting or operational decisions.

The Greater Edwards Aquifer Alliance recommends that the Texas Legislature act immediately to:

  • Require a moratorium on rock crusher and quarry permits until adequate regulations to protect groundwater, surface water, and neighboring communities have been promulgated.
  • Empower local elected officials to regulate crusher/quarry siting, land use compatibility, air and water quality.
  • Prohibit rock crushers or quarries within one-half mile of residences, churches, schools, hospitals, day care providers, parks, or surface water used as a public drinking water supply.
  • Prohibit rock crushers or quarries where the county commissioners court has determined that the proposed rock crusher or quarry will impair the health, safety, and welfare of county residents.
  • Require an accurate determination of the effect of any proposed crusher or quarry on groundwater, surface water, and roads prior to permitting.
  • Require notice of any proposed crusher or quarry to land owners within one mile of property boundaries.
  • Require operational methods and equipment to protect air and water quality.
  • Control blasting, heavy equipment operation, stockpiling and transportation operations to protect surrounding neighbors and water supplies.
  • Limit the maximum active mining area and maximum quarry depth.
  • Control blasting by limiting the charge size so that physical motion, dust, or noise does not damage adjacent property.
  • Require that blasting areas be covered to contain dust.
  • Limit the size, weight and number of vehicles from the quarry or crusher using public roads.
The interpretation of vested rights (“grandfathering”) has become one of the most crucial issues in determining the shape of new development and, ultimately, how our cities will look and function for years to come. Legal challenges to municipal enforcement of regulations adopted to protect the aquifer, protect the public from flooding, preserve trees and open space for the public’s enjoyment, prescribe density limits, and even require sidewalks or ban unsightly billboards have become routine.

Opinions on the subject range from those who aver that the only inducement Texas has to attract economic development is the low cost of doing business, (ergo, interpretation of vested rights should favor circumvention of existing ordinances) to those who believe that municipalities have the right and the duty to protect the public’s heath, safety and welfare by every means available, including strict interpretation of vested rights that enable a city to retain its rights to enforce its Unified Development Code.

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